LU decomposition

Hi, i´m a begginer(looser) in matlab and i don´t know, where is problem in this script. Please help me and thanks for tips.

 function [L, U, P] = LURozklad(A)
  P = eye(size(A));
  L = P;
  A_pred = A;
  P_pred = P;

for k = 1:size(A) - 1
    r = IPR(A, k, k);
    A_pred = A;
    A = VymenaRadkuMatice(A, k, r);
    P_pred = VymenaRadkuMatice(P_pred, k, r);
    P = P_predchozi;

      for i = k + 1:size(A)
          m_ik = A(i, k)/A(k, k);

      for j = k + 1:size(A)
          A(i, j) = A(i, j) - m_ik * A(k, j);
      end
      A(i, k) = m_ik;

end

printf('matice A: ', A);

for i = 2:size(A)
    for j = 1:size(A)
        if i > j
            L(i, j) = A(i, j);
        end
    end
end

printf('matice L: ', L);
for i = 1:size(A)
    for j = 1:size(A)
        if i <= j
            U(i, j) = A(i, j);
        end
    end
end

printf('matice U: ', U);

P = P_predchozi;
printf('matice P:', P);
end

function [r] = IndexPivotnihoRadku(A, OdRadku, IndexSloupce)
MaxHodnota = 0;
for i = OdRadku:size(A)
if abs(A(i,IndexSloupce)) > MaxHodnota
MaxHodnota = abs(A(i,IndexSloupce));
r = i;
end
end
function [A] = VymenaRadkuMatice(A, radek1, radek2)
PomocnyRadek = A(radek1,:);
A(radek1, :) = A(radek2,:);
A(radek2, :) = PomocnyRadek;
end
function printf(string, value)
disp(string);
disp(value);
end
end
end

[Jan]

Please explain, why you are thinking, that this function has a problem.